Now that all callers use ->t_dfops, the xfs_bmapi_write() dfops
parameter is no longer necessary. Remove it and access ->t_dfops
directly. This patch does not change behavior.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Attach ->t_dfops for all remaining callers of xfs_bmapi_write().
This prepares the latter to no longer require a separate dfops
parameter.

Note that xfs_symlink() already uses ->t_dfops. Fix up the local
references for consistency.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

xfs_dquot_disk_alloc() receives a transaction from the caller and
passes a local dfops along to xfs_bmapi_write(). If we attach this
dfops to the transaction, we have to make sure to clear it before
returning to avoid invalid access of stack memory.

Since xfs_qm_dqread_alloc() is the only caller, pull dfops into the
caller and attach it to the transaction to eliminate this pattern
entirely.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Now that xfs_da_args->dfops is always assigned from a ->t_dfops
pointer (or one that is immediately attached), replace all
downstream accesses of the former with the latter and remove the
field from struct xfs_da_args.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Attach the local dfops to ->t_dfops of the extent split transaction.
Since this is the only caller of xfs_bmap_split_extent_at(), remove
the dfops parameter as well.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Now that the attribute fork add tx carries dfops along with the
transaction, it is unnecessary to pass it down the stack. Remove the
dfops parameter and access ->t_dfops directly where necessary. This
patch does not change behavior.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Attach the local dfops to the transaction allocated for xattr add
and remove operations. Add an earlier initialization in
xfs_attr_remove() to ensure the structure is valid if it remains
unused at transaction commit time.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Log recovery passes down a central dfops structure to recovery
handlers for bui and cui log items. Each of these handlers allocates
and commits a transaction and defers any remaining operations to be
completed by the main recovery sequence.

Since dfops outlives the transaction in this context, set and clear
->t_dfops appropriately such that the *_finish_item() paths and
below (i.e., xfs_bmapi*()) can expect to find the dfops in the
transaction without it being committed with the dfops attached. This
is required because transaction commit expects that an associated
dfops is finished and in this context the dfops may be populated at
commit time.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

All callers of the directory create, rename and remove interfaces
already associate the dfops with the transaction. Drop the dfops
parameters in these calls in preparation for further cleanups in the
layers below. This patch does not change behavior.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

The inode free callchain starting in xfs_inactive_ifree() already
associates its dfops with the transaction. It still passes the dfops
on the stack down through xfs_difree_inobt(), however.

Clean up the call stack and reference dfops directly from the
transaction. This patch does not change behavior.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

The ->t_agfl_dfops field is currently used to defer agfl block frees
from associated transaction contexts. While all known problematic
contexts have already been updated to use ->t_agfl_dfops, the
broader goal is defer agfl frees from all callers that already use a
deferred operations structure. Further, the transaction field
facilitates a good amount of code clean up where the transaction and
dfops have historically been passed down through the stack
separately.

Rename the field to something more generic to prepare to use it as
such throughout XFS. This patch does not change behavior.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

A couple COW fork unwritten extent conversion helpers pass an
uninitialized dfops pointer to xfs_bmapi_write(). This does not
cause problems because conversion does not use a transaction or the
dfops structure for the COW fork.  Drop the uninitialized usage of
dfops in these codepaths and pass NULL along to xfs_bmapi_write()
instead.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NCarlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Switch to using the iomap_page structure for checking sub-page uptodate
status and track sub-page I/O completion status, and remove large
quantities of boilerplate code working around buffer heads.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

After already supporting a simple implementation of buffered writes for
the blocksize == PAGE_SIZE case in the last commit this adds full support
even for smaller block sizes.   There are three bits of per-block
information in the buffer_head structure that really matter for the iomap
read and write path:

 - uptodate status (BH_uptodate)
 - marked as currently under read I/O (BH_Async_Read)
 - marked as currently under write I/O (BH_Async_Write)

Instead of having new per-block structures this now adds a per-page
structure called struct iomap_page to track this information in a slightly
different form:

 - a bitmap for the per-block uptodate status.  For worst case of a 64k
   page size system this bitmap needs to contain 128 bits.  For the
   typical 4k page size case it only needs 8 bits, although we still
   need a full unsigned long due to the way the atomic bitmap API works.
 - two atomic_t counters are used to track the outstanding read and write
   counts

There is quite a bit of boilerplate code as the buffered I/O path uses
various helper methods, but the actual code is very straight forward.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Disable the IOMAP_F_BUFFER_HEAD flag on file systems with a block size
equal to the page size, and deal with pages without buffer heads in
writeback.  Thanks to the previous refactoring this is basically trivial
now.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Rejuggle how we deal with the different error vs non-error and have
ioends vs not have ioend cases to keep the fast path streamlined, and
the duplicate code at a minimum.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

This helper only has two callers, one of them with a constant error
argument.  Remove it to make pending changes to the code a little easier.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

This keeps it in a single place so it can be made otional more easily.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Calculate all information for the bio based on the passed in information
without requiring a buffer_head structure.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Simplify the way we check for a valid imap - we know we have a valid
mapping after xfs_map_blocks returned successfully, and we know we can
call xfs_imap_valid on any imap, as it will always fail on a
zero-initialized map.

We can also remove the xfs_imap_valid function and fold it into
xfs_map_blocks now.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

xfs_bmapi_read adds zero value in xfs_map_blocks.  Replace it with a
direct call to the low-level extent lookup function.

Note that we now always pass a 0 length to the trace points as we ask
for an unspecified len.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

We only have one caller left, and open coding the simple extent list
lookup in it allows us to make the code both more understandable and
reuse calculations and variables already present.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

xfs_writepage_map() iterates over the bufferheads on a page to decide
what sort of IO to do and what actions to take.  However, when it comes
to reflink and deciding when it needs to execute a COW operation, we no
longer look at the bufferhead state but instead we ignore than and look
up internal state held in the COW fork extent list.

This means xfs_writepage_map() is somewhat confused. It does stuff, then
ignores it, then tries to handle the impedence mismatch by shovelling the
results inside the existing mapping code.  It works, but it's a bit of a
mess and it makes it hard to fix the cached map bug that the writepage
code currently has.

To unify the two different mechanisms, we first have to choose a direction.
That's already been set - we're de-emphasising bufferheads so they are no
longer a control structure as we need to do taht to allow for eventual
removal.  Hence we need to move away from looking at bufferhead state to
determine what operations we need to perform.

We can't completely get rid of bufferheads yet - they do contain some
state that is absolutely necessary, such as whether that part of the page
contains valid data or not (buffer_uptodate()).  Other state in the
bufferhead is redundant:

	BH_dirty - the page is dirty, so we can ignore this and just
		write it
	BH_delay - we have delalloc extent info in the DATA fork extent
		tree
	BH_unwritten - same as BH_delay
	BH_mapped - indicates we've already used it once for IO and it is
		mapped to a disk address. Needs to be ignored for COW
		blocks.

The BH_mapped flag is an interesting case - it's supposed to indicate that
it's already mapped to disk and so we can just use it "as is".  In theory,
we don't even have to do an extent lookup to find where to write it too,
but we have to do that anyway to determine we are actually writing over a
valid extent.  Hence it's not even serving the purpose of avoiding a an
extent lookup during writeback, and so we can pretty much ignore it.
Especially as we have to ignore it for COW operations...

Therefore, use the extent map as the source of information to tell us
what actions we need to take and what sort of IO we should perform.  The
first step is to have xfs_map_blocks() set the io type according to what
it looks up.  This means it can easily handle both normal overwrite and
COW cases.  The only thing we also need to add is the ability to return
hole mappings.

We need to return and cache hole mappings now for the case of multiple
blocks per page.  We no longer use the BH_mapped to indicate a block over
a hole, so we have to get that info from xfs_map_blocks().  We cache it so
that holes that span two pages don't need separate lookups.  This allows us
to avoid ever doing write IO over a hole, too.

Now that we have xfs_map_blocks() returning both a cached map and the type
of IO we need to perform, we can rewrite xfs_writepage_map() to drop all
the bufferhead control. It's also much simplified because it doesn't need
to explicitly handle COW operations.  Instead of iterating bufferheads, it
iterates blocks within the page and then looks up what per-block state is
required from the appropriate bufferhead.  It then validates the cached
map, and if it's not valid, we get a new map.  If we don't get a valid map
or it's over a hole, we skip the block.

At this point, we have to remap the bufferhead via xfs_map_at_offset().
As previously noted, we had to do this even if the buffer was already
mapped as the mapping would be stale for XFS_IO_DELALLOC, XFS_IO_UNWRITTEN
and XFS_IO_COW IO types.  With xfs_map_blocks() now controlling the type,
even XFS_IO_OVERWRITE types need remapping, as converted-but-not-yet-
written delalloc extents beyond EOF can be reported at XFS_IO_OVERWRITE.
Bufferheads that span such regions still need their BH_Delay flags cleared
and their block numbers calculated, so we now unconditionally map each
bufferhead before submission.

But wait! There's more - remember the old "treat unwritten extents as
holes on read" hack?  Yeah, that means we can have a dirty page with
unmapped, unwritten bufferheads that contain data!  What makes these so
special is that the unwritten "hole" bufferheads do not have a valid block
device pointer, so if we attempt to write them xfs_add_to_ioend() blows
up. So we make xfs_map_at_offset() do the "realtime or data device"
lookup from the inode and ignore what was or wasn't put into the
bufferhead when the buffer was instantiated.

The astute reader will have realised by now that this code treats
unwritten extents in multiple-blocks-per-page situations differently.
If we get any combination of unwritten blocks on a dirty page that contain
valid data in the page, we're going to convert them to real extents.  This
can actually be a win, because it means that pages with interleaving
unwritten and written blocks will get converted to a single written extent
with zeros replacing the interspersed unwritten blocks.  This is actually
good for reducing extent list and conversion overhead, and it means we
issue a contiguous IO instead of lots of little ones.  The downside is
that we use up a little extra IO bandwidth.  Neither of these seem like a
bad thing given that spinning disks are seek sensitive, and SSDs/pmem have
bandwidth to burn and the lower Io latency/CPU overhead of fewer, larger
IOs will result in better performance on them...

As a result of all this, the only state we actually care about from the
bufferhead is a single flag - BH_Uptodate. We still use the bufferhead to
pass some information to the bio via xfs_add_to_ioend(), but that is
trivial to separate and pass explicitly.  This means we really only need
1 bit of state per block per page from the buffered write path in the
writeback path.  Everything else we do with the bufferhead is purely to
make the buffered IO front end continue to work correctly. i.e we've
pretty much marginalised bufferheads in the writeback path completely.
Signed-off-By: NDave Chinner <dchinner@redhat.com>
[hch: forward port, refactor and split off bits into other commits]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Calling it file_offset makes the usage more clear, especially with
a new poffset variable that will be added soon for the offset inside
the page.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

We can handle the existing cow mapping case as a special case directly
in xfs_writepage_map, and share code for allocating delalloc blocks
with regular I/O in xfs_map_blocks.  This means we need to always
call xfs_map_blocks for reflink inodes, but we can still skip most of
the work if it turns out that there is no COW mapping overlapping the
current block.

As a subtle detail we need to start caching holes in the wpc to deal
with the case of COW reservations between EOF.  But we'll need that
infrastructure later anyway, so this is no big deal.

Based on a patch from Dave Chinner.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

We already have to check for overlapping COW extents everytime we
come back to a page in xfs_writepage_map / xfs_map_cow, so this
additional trim is not required.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

We want to be able to use the extent state as a reliably indicator for
the type of I/O, and stop using the buffer head state.  For this we
need to stop using the XFS_BMAPI_IGSTATE so that we don't see merged
extents of different types.

Based on a patch from Dave Chinner.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Finding a buffer that isn't uptodate doesn't invalidate the mapping for
any given block.  The last_sector check will already take care of starting
another ioend as soon as we find any non-update buffer, and if the current
mapping doesn't include the next uptodate buffer the xfs_imap_valid check
will take care of it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

We already track the page uptodate status based on the buffer uptodate
status, which is updated whenever reading or zeroing blocks.

This code has been there since commit a ptool commit in 2002, which
claims to:

    "merge" the 2.4 fsx fix for block size < page size to 2.5.  This needed
    major changes to actually fit.

and isn't present in other writepage implementations.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Both callers want the same looking, so do it only once.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Instead of looking at the buffer heads to see if a block is delalloc just
call xfs_bmap_punch_delalloc_range on the whole page - this will leave
any non-delalloc block intact and handle the iteration for us.  As a side
effect one more place stops caring about buffer heads and we can remove the
xfs_check_page_type function entirely.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

For file systems with a block size that equals the page size we never do
partial reads, so we can use the buffer_head-less iomap versions of
readpage and readpages without conflicting with the buffer_head structures
create later in write_begin.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

sgid directories have special semantics, making newly created files in
the directory belong to the group of the directory, and newly created
subdirectories will also become sgid.  This is historically used for
group-shared directories.

But group directories writable by non-group members should not imply
that such non-group members can magically join the group, so make sure
to clear the sgid bit on non-directories for non-members (but remember
that sgid without group execute means "mandatory locking", just to
confuse things even more).
Reported-by: NJann Horn <jannh@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

smb{2,3}_create_lease_buf() store a lease key in the lease
context for later usage on a lease break.

In most paths, the key is currently sourced from data that
happens to be on the stack near local variables for oplock in
SMB2_open() callers, e.g. from open_shroot(), whereas
smb2_open_file() properly allocates space on its stack for it.

The address of those local variables holding the oplock is then
passed to create_lease_buf handlers via SMB2_open(), and 16
bytes near oplock are used. This causes a stack out-of-bounds
access as reported by KASAN on SMB2.1 and SMB3 mounts (first
out-of-bounds access is shown here):

[  111.528823] BUG: KASAN: stack-out-of-bounds in smb3_create_lease_buf+0x399/0x3b0 [cifs]
[  111.530815] Read of size 8 at addr ffff88010829f249 by task mount.cifs/985
[  111.532838] CPU: 3 PID: 985 Comm: mount.cifs Not tainted 4.18.0-rc3+ #91
[  111.534656] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
[  111.536838] Call Trace:
[  111.537528]  dump_stack+0xc2/0x16b
[  111.540890]  print_address_description+0x6a/0x270
[  111.542185]  kasan_report+0x258/0x380
[  111.544701]  smb3_create_lease_buf+0x399/0x3b0 [cifs]
[  111.546134]  SMB2_open+0x1ef8/0x4b70 [cifs]
[  111.575883]  open_shroot+0x339/0x550 [cifs]
[  111.591969]  smb3_qfs_tcon+0x32c/0x1e60 [cifs]
[  111.617405]  cifs_mount+0x4f3/0x2fc0 [cifs]
[  111.674332]  cifs_smb3_do_mount+0x263/0xf10 [cifs]
[  111.677915]  mount_fs+0x55/0x2b0
[  111.679504]  vfs_kern_mount.part.22+0xaa/0x430
[  111.684511]  do_mount+0xc40/0x2660
[  111.698301]  ksys_mount+0x80/0xd0
[  111.701541]  do_syscall_64+0x14e/0x4b0
[  111.711807]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  111.713665] RIP: 0033:0x7f372385b5fa
[  111.715311] Code: 48 8b 0d 99 78 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 66 78 2c 00 f7 d8 64 89 01 48
[  111.720330] RSP: 002b:00007ffff27049d8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
[  111.722601] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f372385b5fa
[  111.724842] RDX: 000055c2ecdc73b2 RSI: 000055c2ecdc73f9 RDI: 00007ffff270580f
[  111.727083] RBP: 00007ffff2705804 R08: 000055c2ee976060 R09: 0000000000001000
[  111.729319] R10: 0000000000000000 R11: 0000000000000206 R12: 00007f3723f4d000
[  111.731615] R13: 000055c2ee976060 R14: 00007f3723f4f90f R15: 0000000000000000

[  111.735448] The buggy address belongs to the page:
[  111.737420] page:ffffea000420a7c0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[  111.739890] flags: 0x17ffffc0000000()
[  111.741750] raw: 0017ffffc0000000 0000000000000000 dead000000000200 0000000000000000
[  111.744216] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[  111.746679] page dumped because: kasan: bad access detected

[  111.750482] Memory state around the buggy address:
[  111.752562]  ffff88010829f100: 00 f2 f2 f2 f2 f2 f2 f2 00 00 00 00 00 00 00 00
[  111.754991]  ffff88010829f180: 00 00 f2 f2 00 00 00 00 00 00 00 00 00 00 00 00
[  111.757401] >ffff88010829f200: 00 00 00 00 00 f1 f1 f1 f1 01 f2 f2 f2 f2 f2 f2
[  111.759801]                                               ^
[  111.762034]  ffff88010829f280: f2 02 f2 f2 f2 f2 f2 f2 f2 00 00 00 00 00 00 00
[  111.764486]  ffff88010829f300: f2 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  111.766913] ==================================================================

Lease keys are however already generated and stored in fid data
on open and create paths: pass them down to the lease context
creation handlers and use them.
Suggested-by: NAurélien Aptel <aaptel@suse.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Fixes: b8c32dbb ("CIFS: Request SMB2.1 leases")
Signed-off-by: NStefano Brivio <sbrivio@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

For every request we send, whether it is SMB1 or SMB2+, we attempt to
reconnect tcon (cifs_reconnect_tcon or smb2_reconnect) before carrying
out the request.

So, while server->tcpStatus != CifsNeedReconnect, we wait for the
reconnection to succeed on wait_event_interruptible_timeout(). If it
returns, that means that either the condition was evaluated to true, or
timeout elapsed, or it was interrupted by a signal.

Since we're not handling the case where the process woke up due to a
received signal (-ERESTARTSYS), the next call to
wait_event_interruptible_timeout() will _always_ fail and we end up
looping forever inside either cifs_reconnect_tcon() or smb2_reconnect().

Here's an example of how to trigger that:

$ mount.cifs //foo/share /mnt/test -o
username=foo,password=foo,vers=1.0,hard

(break connection to server before executing bellow cmd)
$ stat -f /mnt/test & sleep 140
[1] 2511

$ ps -aux -q 2511
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root      2511  0.0  0.0  12892  1008 pts/0    S    12:24   0:00 stat -f
/mnt/test

$ kill -9 2511

(wait for a while; process is stuck in the kernel)
$ ps -aux -q 2511
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root      2511 83.2  0.0  12892  1008 pts/0    R    12:24  30:01 stat -f
/mnt/test

By using 'hard' mount point means that cifs.ko will keep retrying
indefinitely, however we must allow the process to be killed otherwise
it would hang the system.
Signed-off-by: NPaulo Alcantara <palcantara@suse.de>
Cc: stable@vger.kernel.org
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

A "small" CIFS buffer is not big enough in general to hold a
setacl request for SMB2, and we end up overflowing the buffer in
send_set_info(). For instance:

 # mount.cifs //127.0.0.1/test /mnt/test -o username=test,password=test,nounix,cifsacl
 # touch /mnt/test/acltest
 # getcifsacl /mnt/test/acltest
 REVISION:0x1
 CONTROL:0x9004
 OWNER:S-1-5-21-2926364953-924364008-418108241-1000
 GROUP:S-1-22-2-1001
 ACL:S-1-5-21-2926364953-924364008-418108241-1000:ALLOWED/0x0/0x1e01ff
 ACL:S-1-22-2-1001:ALLOWED/0x0/R
 ACL:S-1-22-2-1001:ALLOWED/0x0/R
 ACL:S-1-5-21-2926364953-924364008-418108241-1000:ALLOWED/0x0/0x1e01ff
 ACL:S-1-1-0:ALLOWED/0x0/R
 # setcifsacl -a "ACL:S-1-22-2-1004:ALLOWED/0x0/R" /mnt/test/acltest

this setacl will cause the following KASAN splat:

[  330.777927] BUG: KASAN: slab-out-of-bounds in send_set_info+0x4dd/0xc20 [cifs]
[  330.779696] Write of size 696 at addr ffff88010d5e2860 by task setcifsacl/1012

[  330.781882] CPU: 1 PID: 1012 Comm: setcifsacl Not tainted 4.18.0-rc2+ #2
[  330.783140] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
[  330.784395] Call Trace:
[  330.784789]  dump_stack+0xc2/0x16b
[  330.786777]  print_address_description+0x6a/0x270
[  330.787520]  kasan_report+0x258/0x380
[  330.788845]  memcpy+0x34/0x50
[  330.789369]  send_set_info+0x4dd/0xc20 [cifs]
[  330.799511]  SMB2_set_acl+0x76/0xa0 [cifs]
[  330.801395]  set_smb2_acl+0x7ac/0xf30 [cifs]
[  330.830888]  cifs_xattr_set+0x963/0xe40 [cifs]
[  330.840367]  __vfs_setxattr+0x84/0xb0
[  330.842060]  __vfs_setxattr_noperm+0xe6/0x370
[  330.843848]  vfs_setxattr+0xc2/0xd0
[  330.845519]  setxattr+0x258/0x320
[  330.859211]  path_setxattr+0x15b/0x1b0
[  330.864392]  __x64_sys_setxattr+0xc0/0x160
[  330.866133]  do_syscall_64+0x14e/0x4b0
[  330.876631]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  330.878503] RIP: 0033:0x7ff2e507db0a
[  330.880151] Code: 48 8b 0d 89 93 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 bc 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 56 93 2c 00 f7 d8 64 89 01 48
[  330.885358] RSP: 002b:00007ffdc4903c18 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc
[  330.887733] RAX: ffffffffffffffda RBX: 000055d1170de140 RCX: 00007ff2e507db0a
[  330.890067] RDX: 000055d1170de7d0 RSI: 000055d115b39184 RDI: 00007ffdc4904818
[  330.892410] RBP: 0000000000000001 R08: 0000000000000000 R09: 000055d1170de7e4
[  330.894785] R10: 00000000000002b8 R11: 0000000000000246 R12: 0000000000000007
[  330.897148] R13: 000055d1170de0c0 R14: 0000000000000008 R15: 000055d1170de550

[  330.901057] Allocated by task 1012:
[  330.902888]  kasan_kmalloc+0xa0/0xd0
[  330.904714]  kmem_cache_alloc+0xc8/0x1d0
[  330.906615]  mempool_alloc+0x11e/0x380
[  330.908496]  cifs_small_buf_get+0x35/0x60 [cifs]
[  330.910510]  smb2_plain_req_init+0x4a/0xd60 [cifs]
[  330.912551]  send_set_info+0x198/0xc20 [cifs]
[  330.914535]  SMB2_set_acl+0x76/0xa0 [cifs]
[  330.916465]  set_smb2_acl+0x7ac/0xf30 [cifs]
[  330.918453]  cifs_xattr_set+0x963/0xe40 [cifs]
[  330.920426]  __vfs_setxattr+0x84/0xb0
[  330.922284]  __vfs_setxattr_noperm+0xe6/0x370
[  330.924213]  vfs_setxattr+0xc2/0xd0
[  330.926008]  setxattr+0x258/0x320
[  330.927762]  path_setxattr+0x15b/0x1b0
[  330.929592]  __x64_sys_setxattr+0xc0/0x160
[  330.931459]  do_syscall_64+0x14e/0x4b0
[  330.933314]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

[  330.936843] Freed by task 0:
[  330.938588] (stack is not available)

[  330.941886] The buggy address belongs to the object at ffff88010d5e2800
 which belongs to the cache cifs_small_rq of size 448
[  330.946362] The buggy address is located 96 bytes inside of
 448-byte region [ffff88010d5e2800, ffff88010d5e29c0)
[  330.950722] The buggy address belongs to the page:
[  330.952789] page:ffffea0004357880 count:1 mapcount:0 mapping:ffff880108fdca80 index:0x0 compound_mapcount: 0
[  330.955665] flags: 0x17ffffc0008100(slab|head)
[  330.957760] raw: 0017ffffc0008100 dead000000000100 dead000000000200 ffff880108fdca80
[  330.960356] raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
[  330.963005] page dumped because: kasan: bad access detected

[  330.967039] Memory state around the buggy address:
[  330.969255]  ffff88010d5e2880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  330.971833]  ffff88010d5e2900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  330.974397] >ffff88010d5e2980: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
[  330.976956]                                            ^
[  330.979226]  ffff88010d5e2a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  330.981755]  ffff88010d5e2a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  330.984225] ==================================================================

Fix this by allocating a regular CIFS buffer in
smb2_plain_req_init() if the request command is SMB2_SET_INFO.
Reported-by: NJianhong Yin <jiyin@redhat.com>
Fixes: 366ed846 ("cifs: Use smb 2 - 3 and cifsacl mount options setacl function")
CC: Stable <stable@vger.kernel.org>
Signed-off-by: NStefano Brivio <sbrivio@redhat.com>
Reviewed-and-tested-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

This patch fixes a memory leak when doing a setxattr(2) in SMB2+.
Signed-off-by: NPaulo Alcantara <palcantara@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>

SMB1 mounting broke in commit 35e2cc1b
("cifs: Use correct packet length in SMB2_TRANSFORM header")
Fix it and also rename smb2_rqst_len to smb_rqst_len
to make it less unobvious that the function is also called from
CIFS/SMB1

Good job by Paulo reviewing and cleaning up Ronnie's original patch.
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: NPaulo Alcantara <palcantara@suse.de>
Signed-off-by: NSteve French <stfrench@microsoft.com>